Someone's got an opinion on Justin Bieber and Selena Gomez's romantic reunion: Taylor Swift! The 23-year-old singer songwriter sat right next to BFF Gomez, 20, during Sunday's May 19 Billboard Music Awards in Las Vegas, and watched as Bieber, 19, accepted two awards onstage (including a Milestone Award, where he was met with boos).

Backstage, the "We Are Never Ever Getting Back Together" crooner, clad in a blue sequined minidress by Zuhair Murad, encountered Gomez giving Bieber an affectionate congrats with a hug and a kiss. As caught on camera, Swift responded by sticking her tongue out -- in real or mock disgust.

Swift may simply be as weary as millions of fans by Gomez and Bieber perpetual off-and-on-and-off status; the pair split back in January, only to reunite affectionately several times. Currently single herself, Swift's own evening was triumphant even without a date: She wont eight awards that night, including Top Artist. The star was even willing to mock her own less-than-stellar love life while acknowledging her fans at the podium.